The Trinity Test: July 16, 1945

Today marks the sixty-first anniversary of the dawn of the nuclear age. On the morning of July 16, 1945, an atomic bomb was detonated at the Trinity test site in the desert between Alamogordo and Socorro, New Mexico. The explosion demonstrated the power of atomic weaponry and validated the work of scientists from the Manhattan Project, a top-secret government program led by General Leslie R. Groves. Physicists from Site Y, the code name for the project's facility at Los Alamos, New Mexico, had designed an implosion-style atomic bomb using fissionable material from laboratories at Oak Ridge, Tennessee and Hanford, Washington. This implosion bomb, dubbed "Gadget", consisted of a grapefruit-sized plutonium sphere surrounded by ordinary explosives. According to theory, detonating the explosives would reduce the plutonium to the size of a walnut, obtaining the critical mass necessary for an atomic explosion. The Trinity test proved the soundness of Gadget's complex design and changed the course of history.

Preparations for the Trinity test began months in advance. Although General Groves wanted to test Gadget at a military base in California, his dislike of the local commander, George Patton, resulted in the selection of the Alamogordo Bombing Range instead. In May 1945, technicians calibarted instrumentation for the Trinity blast by detonating 108 tons of TNT on a wooden platform near Trinity's ground zero. The "100 Ton Test" threaded the high explosives with tubes containing 1000 curies of fission products. As a result of the TNT blast, scientists from Los Alamos learned how these materials would be distributed by an atomic explosion. After the "100 Ton Test", workers built at 100-ft. tower at Trinity ground zero and installed seismographic and photographic equipment. Other instruments were setup to record radioactivity, temperature, and air pressure.

On July 12, 1945, Gadget's plutonium core arrived from Los Alamos by military convoy at an abandoned farmhouse two miles south of the Trinity test site. The core consisted of two parts, each of which was transported in a shock-mounted, corrosion-resistant carrying case with integral thermometers. On July 14, the assembled core was moved to a canvas tent at the test site, where a two-man team of "G-Engineers" completed the pit assembly. Although Marshall Holloway and Phillip Morrison had filled the assembly once before, the plug of active material became stuck inside Gadget's explosive shell. Wisely, the physicists waited for the heat to be conducted away from the rest of the pit. "In less than a minute", Holloway remembered, "it just fell in and that crisis was over." Later that day, Gadget was hoisted to the top of the 100-foot tower at ground zero. On July 15, the G-Engineers installed the detonators, completing the bomb's assembly.

The early morning hours of July 16, 1945 brought a severe thunderstorm to a part of the New Mexican desert called La Journada del Muerto, literally "The Journey of Death". Concerns that the rainfall could increase the amount of radioactive fallout and interfere with the test results delayed the Trinity shot until 5:29:45 A.M. Mountain War Time. When Gadget was finally detonated, the atomic explosion created a flash of light brighter than a dozen suns. According to observers, light was seen over the entire state of New Mexico and in parts of Texas and Arizona. A mushroom cloud rose to over 38,000 feet and man-made thunder echoed off the Oscuro Mountains. The heat of the explosion reached temperatures 10,000 times hotter than the surface of the sun, melting the sandy soil around the tower and forming a glassy crust that would become known as "trinitite".

Although the origin of the code name "Trinity" remains unclear, most historians credit J. Robert Oppenheimer, the scientific director of the Manhattan Project, with its usage. A theoretical physicist, Oppenheimer was also a student of Sanskrit literature and familiar with the divine Hindu trinity of Brahma, the Creator; Vishnu, the Preserver; and Shiva, the Destroyer. According to legend, Dr. Oppenheimer read the following passage from the Bhagavad-Gita after the conclusion of the Trinity test: "I am become Death, the Shatterer of Worlds".

Resources

http://nuclearweaponarchive.org/Usa/Tests/Trinity.html

http://www.abomb1.org/trinity/trinity1.html

http://www.lanl.gov/history/people/P_Morrison.shtml

http://encarta.msn.com/encyclopedia_701610456_2/Manhattan_Project.html

http://www.2020hindsight.org/2005/07/12/

http://geology.about.com/library/bl/images/bltrinitite.htm

http://en.wikipedia.org/wiki/Leslie_Groves

See also:

http://cr4.globalspec.com/blogentry/5450/Chien-Shiung-Wu-May-13-1912-February-16-1997